Omarosa Manigault Newman, the once-loyal aide to President Trump who has written a new tell-all book containing explosive allegations about her former boss, said Monday that she believes Trump was lying when he claimed in a phone call in December that he knew nothing about her dismissal by White House Chief of Staff John F. Kelly.

In a combative appearance on NBC’s “Today” show, Manigault Newman shared an audio recording of the phone conversation that she says she had with Trump the day after she was fired from his administration.

She also denounced the White House’s handling of her firing, claiming that the two-hour Situation Room meeting in which she was let go amounts to “false imprisonment.”

“There is a complete organization between the two of them,” Manigault Newman said of Trump and Kelly. “He probably instructed General Kelly to do it so that he could keep his hands clean when he spoke to me. I’m wondering, is he sincere?”

She added: “Is General Kelly running this country, or is the president running this country?”

Trump fired back at Manigault Newman with a Monday morning tweet in which he attacked his former aide as “vicious, but not smart” and claimed that “people in the White House hated her.”

“Wacky Omarosa, who got fired 3 times on the Apprentice, now got fired for the last time,” Trump said. “She never made it, never will. She begged me for a job, tears in her eyes, I said Ok.”

Trump said he would “rarely see” Manigault Newman in the White House, a claim that contradicts reports that she enjoyed a close relationship with the president.

In two follow-up tweets, Trump continued to disparage his former aide, saying he had “heard really bad things” about her and claiming that she “would constantly miss meetings & work.”

“When Gen. Kelly came on board he told me she was a loser & nothing but problems. I told him to try working it out, if possible, because she only said GREAT things about me — until she got fired!” Trump said.

He added that while it was “not presidential” to attack her, he was doing so because he believes the media will be trying to make her “look as legitimate as possible.”

The Washington Post had previously reported on Manigault Newman’s account of the conversation with Trump the day after her firing. On the recording aired Monday morning, Trump is heard expressing surprise that Manigault Newman was fired.

“Omarosa, what’s going on?” Trump asks. “I just saw on the news that you’re thinking about leaving. What happened?”

Manigault Newman responds that Kelly told her that she had been dismissed.

“No. Nobody even told me about it,” Trump replies. “You know they run a big operation, but I didn’t know it. I didn’t know that. Goddammit. I don’t love you leaving at all.”

In an appearance on Fox News on Monday morning, White House spokesman Hogan Gidley declined to say whether Trump had specifically ordered Manigault Newman’s firing but blasted her claims that Kelly was in charge as “absolutely ludicrous and ridiculous.”

“The president makes the decisions in this White House,” Gidley said. “I’m not going to get into the tick tock of who knew what and when.”

Trump tweeted later Monday that Manigault Newman “already has a fully signed Non-Disclosure Agreement!” It was not immediately clear what the president meant.

The Washington Post reported Friday that after being fired, Manigault Newman declined a $15,000-a-month job offer with Trump’s reelection campaign, which came with a “companion agreement” including nondisclosure and nondisparagement provisions. Copies of both documents were obtained by The Post.

In an interview later Monday on MSNBC, Manigault Newman claimed that the White House has seven boxes of her personal belongings that it is refusing to give back to her because she declined to sign the agreement with Trump’s campaign.

She also pushed back against Trump’s description of her as “not smart.”

“I think it’s sad that with all the things that’s going on in the country that he would take time out to insult me and to insult my intelligence,” she said. “This is his pattern with African Americans, and he doesn’t know how to control himself.”

The release of the audio comes one day after Manigault Newman shared a separate recording of what she says is the conversation in which Kelly informed her she was being fired.

In an appearance on NBC’s “Meet the Press” on Sunday, Manigault Newman said she made the recording in the Situation Room — a revelation that White House press secretary Sarah Huckabee Sanders said that, if true, “shows a blatant disregard for our national security.”

Asked during Monday’s “Today” show interview about how she made the recording, Manigault Newman declined to answer, saying only, “I’ll just leave that to your imagination.”

She defended making recordings of her calls and meetings with Trump, Kelly and others, saying that if she hadn’t, the White House would have claimed that the conversations never occurred.

“Had I not recorded this, people would say, ‘She has a credibility issue,’ ” she said.

She also maintained that she has heard a three-minute audio recording on which Trump uses the n-word multiple times as host of “The Apprentice.” Manigault Newman has written that such a recording exists but has not provided evidence.

“He was talking about some African Americans in the production during the course of ‘The Apprentice,’ which is unacceptable,” Manigault Newman said, urging reporters to ask Trump whether he has ever used the racial epithet.

And she took issue with the way in which the meeting to discuss her departure from the White House was handled, telling NBC’s Savannah Guthrie, “It’s not acceptable for four men to take a woman into a room, lock the door, and tell her that she cannot leave.”

“The moment I said I would like to leave and they said I can’t go, it became false imprisonment,” she said.

Gidley disputed Manigault Newman’s account of the meeting, although he declined to go into detail.

“More will come out about this, but the way she characterizes that meeting is completely false,” Gidley said. “Apparently telling the truth wasn’t paying her bills, so she decided to switch her story just to make a quick buck.”

Manigault Newman also said Monday that she believes Trump is mentally unfit to serve as president, arguing that if Trump was telling the truth in his phone call to her the day after her firing, then he is not aware of what’s going on in his own White House.